Pantothenic Acid (Monograph)

Drug class: Vitamin B Complex
ATC class: A11HA30
VA class: VT107
CAS number: 79-83-4

Medically reviewed by Drugs.com on Dec 23, 2024. Written by ASHP.

Introduction

Pantothenic acid is a water-soluble, B complex vitamin.

Uses for Pantothenic Acid

Pantothenic acid deficiency has rarely been identified in humans except in conjunction with deficiency of other B complex vitamins. Diagnosis of pantothenic acid deficiency is aided by a serum pantothenate concentration of less than 50 mcg/mL. Whenever possible, poor dietary habits should be corrected, and some clinicians recommend administration of multivitamin preparations containing pantothenic acid in patients with vitamin deficiencies since poor dietary habits may result in concurrent deficiencies. Some cases of peripheral neuritis, muscular cramps in the legs associated with pregnancy and alcoholism, burning feet syndrome, and glossitis refractory to other vitamin therapy have responded to pantothenic acid. In one study, patients with celiac disease who did not respond to a gluten-free diet did improve when given pantothenate.

Dietary Requirements

The National Academy of Sciences (NAS) has issued a comprehensive set of Recommended Dietary Allowances (RDAs) as reference values for dietary nutrient intakes since 1941. In 1997, the NAS Food and Nutrition Board (part of the Institute of Medicine [IOM]) announced that they would begin issuing revised nutrient recommendations that would replace RDAs with Dietary Reference Intakes (DRIs). DRIs are reference values that can be used for planning and assessing diets for healthy populations and for many other purposes and that encompass the Estimated Average Requirement (EAR), the Recommended Dietary Allowance (RDA), the Adequate Intake (AI), and the Tolerable Upper Intake Level (UL).

Because of limitations of current knowledge (i.e., uncertainties in the accuracy of published data, limited number of individuals studied, lack of information on the relationship between intake and absorption and storage of the vitamin), the NAS was unable to establish EARs and RDAs for pantothenic acid. After weighing the available current evidence, the NAS decided that only AIs could be established for pantothenic acid, regardless of the life-stage or gender.

The NAS established an AI for pantothenic acid for adults based on intake adequate to replace urinary excretion. The AI for children and adolescents 1–18 years of age was based on adult values. An AI has been set for infants up to 6 months of age based on observed mean pantothenic acid intake in infants fed principally human milk. An AI for infants 6–12 months of age has been set based on the AI for younger infants and the AI for adults.

Pantothenic acid deficiency has been observed only in individuals fed diets virtually devoid of pantothenic acid and in individuals receiving a pantothenic acid metabolic antagonist (omega-methylpantothenic acid). Adequate intakes of pantothenic acid can be obtained through consumption of foodstuffs. Good sources of pantothenic acid include chicken, beef, potatoes, oat cereals, tomato products, liver, kidney, yeast, egg yolk, broccoli, and whole grains.

For specific information on currently recommended AIs for pantothenic acid for various life-stage and gender groups, see Dosage: Dietary and Replacement Requirements, under Dosage and Administration.

Other Uses

Dexpanthenol has been used to stimulate intestinal peristalsis (e.g., following major abdominal surgery, to relieve postoperative or postpartum flatus); however, well-controlled trials have failed to show it to be of any benefit.

Dexpanthenol has been used topically to relieve itching and promote healing of various minor dermatoses.

Pantothenic acid is not generally accepted as having any therapeutic use, but it has been prescribed for streptomycin neurotoxicity, salicylate toxicity, gray hair, alopecia, catarrhal respiratory disorders, osteoarthritis, diabetic neuropathy, psychiatric states, and to ameliorate untoward symptoms during thyroid therapy in patients with congenital hypothyroidism (cretinism).

Pantothenic Acid Dosage and Administration

Administration

Calcium pantothenate and pantothenic acid are usually administered orally; dexpanthenol is usually administered by IM injection, but may be given slowly by IV infusion. Dexpanthenol may also be administered topically in the form of a cream.

For IV infusion in adults, dexpanthenol injection has been added to a large volume parenteral solution of 5% dextrose or lactated Ringer’s injection and infused slowly.

Dosage

Each 10 mg of calcium pantothenate is equivalent to 9.2 mg of pantothenic acid.

Dietary and Replacement Requirements

The Adequate Intake (AI) (see Uses: Dietary Requirements) of pantothenic acid currently recommended by the National Academy of Sciences (NAS) for healthy infants up to 6 months of age is 1.7 mg (0.24 mg/kg) daily and for those 6–12 months of age is 1.8 mg (0.2 mg/kg) daily. The AI currently recommended by the NAS for healthy children 1–3, 4–8, or 9–13 years of age is 2, 3, or 4 mg daily, respectively. The AI for healthy adolescents 14–18 years of age, adults 19–50 years of age, and adults 51 years of age or older is 5 mg daily.

The AI of pantothenic acid currently recommended by NAS for pregnant women is 6 mg daily and for lactating women 7 mg daily.

Oral Dosage

Oral administration of 5–10 mg of pantothenic acid usually is considered sufficient as a dietary supplement in patients with normal GI absorption.

Parenteral Dosage

To stimulate intestinal peristalsis, 250–500 mg of dexpanthenol has been given IM to adults. Additional doses have been given in 2 hours and repeated every 4–12 hours thereafter as needed. Children have been given 11–12.5 mg/kg IM according to the same schedule. For IV infusion in adults (see Dosage and Administration: Administration), 500 mg of dexpanthenol has been infused slowly. If prompt relief of distention or ileus is not obtained, other methods of treatment should be considered.

Topical Dosage

For topical use to relieve itching or promote healing of various dermatoses, 2% dexpanthenol cream has been applied directly to the affected area once or twice daily, or more often if needed.

Cautions for Pantothenic Acid

Adverse Effects

Pantothenic acid is usually nontoxic even in large doses. One case of heartburn and a few cases of GI cramps have been reported after dexpanthenol administration. Allergic reactions to dexpanthenol have been reported occasionally; however, these reactions have not been directly attributed to the drug. Although isolated reports of itching, tingling, difficulty in breathing, erythema, generalized dermatitis, urticaria, temporary respiratory difficulty (when dexpanthenol injection was administered 5 minutes after succinylcholine had been discontinued), hypotension, persistent (up to 10 days) diarrhea, and agitation have been associated with use of dexpanthenol injection, a causal relationship to the drug has not been established.

Precautions and Contraindications

Dexpanthenol injection should not be used for the management of mechanical obstruction; in these patients, therapy should be directed mainly at correcting the obstruction. The manufacturer of dexpanthenol injection cautions that the management of adynamic ileus includes correction of fluid and electrolyte abnormalities (especially hypokalemia), anemia, and hypoproteinemia; treatment of infection; avoidance of drugs that decrease GI motility; and decompression of the GI tract using nasogastric suction or a long intestinal tube when there is considerable distention.

The manufacturers state that dexpanthenol may prolong bleeding time and, therefore, should be used with extreme caution, if at all, in hemophiliacs. Dexpanthenol should be discontinued if signs of hypersensitivity occur during use.

Pediatric Precautions

Safety and efficacy of dexpanthenol injection in children have not been established.

Mutagenicity and Carcinogenicity

The mutagenic and carcinogenic potentials of dexpanthenol have not been determined.

Pregnancy and Lactation

Pregnancy

Animal reproduction studies have not been performed with dexpanthenol. It is not known whether dexpanthenol can cause fetal harm when administered to pregnant women. Dexpanthenol injection should be used during pregnancy only when clearly needed.

Lactation

Since it is not known whether dexpanthenol is distributed into milk, dexpanthenol injection should be used with caution in nursing women.

Drug Interactions

On theoretical grounds, the manufacturers of dexpanthenol recommend that the drug not be given with or within 12 hours after administration of neostigmine or other parasympathomimetic drugs. Although the clinical importance has not been established, the miotic effects of anticholinesterase ophthalmic preparations (e.g., echothiophate iodide [no longer commercially available in the US], isoflurophate) reportedly may be potentiated by pantothenic acid. It has been reported that dexpanthenol prolonged the muscle relaxant effects of succinylcholine; however, a controlled trial failed to show this effect. The manufacturers recommend that dexpanthenol not be administered within 1 hour of succinylcholine. The manufacturers also warn that rare cases of allergic reactions of unknown cause have occurred during concomitant use of dexpanthenol injection and antibiotics, opiates, and barbiturates.

Pharmacology

In humans, an exogenous source of pantothenic acid is required for intermediary metabolism of carbohydrates, proteins, and lipids. Pantothenic acid is a precursor of coenzyme A which is required for acetylation (acyl-group activation) reactions in gluconeogenesis, in the release of energy from carbohydrates, the synthesis and degradation of fatty acids, and the synthesis of sterols and steroid hormones, porphyrins, acetylcholine, and other compounds. Pantothenic acid also appears to be essential to normal epithelial function.

Dietary deficiency of pantothenic acid has not been clinically identified in humans except in association with pellagra or other deficiency states. Experimentally produced (e.g., with omega-methylpantothenic acid [a metabolic antagonist]or a pantothenic acid-free diet) pantothenic acid deficiency resulted in somnolence, fatigue, headache, paresthesia of the hands and feet followed by hyperreflexia and muscular weakness in the legs, cardiovascular instability, GI complaints, changes in disposition, and increased susceptibility to infections. In animals, dietary deficiency of pantothenic acid results in infertility, abortion, neonatal death, growth retardation, neuromuscular disorders, GI dysfunction, adrenocortical dysfunction, sudden death, and abnormal skin, hair, and feathers.

In large parenteral doses, dexpanthenol has been reported to increase GI peristalsis by stimulating acetylation of choline to acetylcholine; however, the effectiveness of the drug has not been proven.

Pantothenic Acid Pharmacokinetics

Absorption

Pantothenic acid is readily absorbed from the GI tract following oral administration. Normal serum pantothenate concentrations are 100 mcg/mL or greater.

Distribution

Dexpanthenol is readily converted to pantothenic acid which is widely distributed into body tissues, mainly as coenzyme A. Highest concentrations are found in the liver, adrenal glands, heart, and kidneys. Milk of nursing mothers receiving a normal diet contains about 2 mcg of pantothenic acid per mL.

Elimination

About 70% of an oral dose of pantothenic acid is excreted unchanged in urine and about 30% in feces.

Chemistry and Stability

Chemistry

Pantothenic acid is a water-soluble, B complex vitamin which is widely distributed in plant and animal tissues. Rich sources of pantothenic acid include meat, vegetables, cereal grains, legumes, eggs, and milk. Pantothenic acid is optically active; only the dextrorotatory isomer has biologic activity. The vitamin is commercially available as D-pantothenic acid and two synthetic derivatives of D-pantothenic acid: the alcohol (dexpanthenol) and the calcium salt (calcium pantothenate). Pantothenic acid occurs as an unstable, hygroscopic, viscous oil which is freely soluble in water. Calcium pantothenate occurs as a slightly hygroscopic, odorless, white powder with a bitter taste and is freely soluble in water and practically insoluble in alcohol. Dexpanthenol occurs as a clear, slightly hygroscopic, viscous liquid with a slight, characteristic odor and is freely soluble in water and in alcohol. Sodium citrate, citric acid, or hydrochloric acid is added to the commercially available dexpanthenol injection to adjust the pH to 5–7. Air has been replaced with nitrogen in vials of dexpanthenol injection.

Stability

Dexpanthenol is incompatible with alkalis and strong acids. Dexpanthenol injection should be protected from freezing and excessive heat. Calcium pantothenate powder and tablets should be stored in tight containers.

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

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